CA2048209C

CA2048209C - Herbicidal compositions

Info

Publication number: CA2048209C
Application number: CA002048209A
Authority: CA
Inventors: Toshihiro Hirata; Izumi Kobayashi; Nobuyuki Kikkawa; Tetsuo Takematsu
Original assignee: Idemitsu Kosan Co Ltd
Current assignee: Idemitsu Kosan Co Ltd
Priority date: 1990-08-01
Filing date: 1991-07-31
Publication date: 1996-09-17
Anticipated expiration: 2011-07-31
Also published as: DE69116460T2; EP0469406B1; DE69116460D1; US5344810A; CA2048209A1; EP0469406A1; JPH0489409A; ES2084735T3

Abstract

Herbicidal compositions comprising as active ingredients a triazine derivative represented by general formula [I]:

... [I]

and compound represented by general formula [II]:

... [II]

By synergistic effects of active ingredients, the herbicidal compositions show a high herbicidal effect at low dosage and have such a wide range of herbicidal spectrum that the compositions exhibit their high herbicidal effect not only against broad-leaved weeds but also against Gramineae weeds, etc. The compositions have flexibility of treatment to exhibit effectiveness as compared to known herbicides for field crops and crops are free from injury.

Description

2Q48~Q9 E~ERsICIDAL Co~fPOSITIONS

BACKGROUND OF THE INvENTroN
FIELD OF THE INVENTION
The present invention relates to a herbicidal composition comprising triazine derivatives and specific compounds as active ingredients.
STATEMENT OF THE PRIOR ART
Heretofore a variety of herbicides have been developed and have contributed to agricultural productivity and saving labors. However, some herbicides have been used over many years and hence, weeds which are insufficiently controlled are increasing. It has thus been desired to develop herbicides having a wide range of herbicidal spectrum and those effective also against such troublesome weeds.
Also in order to remove environmental pollution problems caused by conventional berbicides, it has been desired to develop berbicides having a high activity at a low dosage.
?~oreover, in order to control weeds emerging non-uniformly over a long period of time, it has been desired to develop herbicides having an excellent residual activities and having flexibility of treatment to exhibit effectiveness even though the treatment is performed over a long period from pre-emergence to a wide range of growing stage of weeds.
Under such a situation, the present inventors f ound that specific, novel triazine derivatives containing a halo alkyl are compounds which show a high herbicidal effect '. 20482o9 against troublesome weeds both by 50il treatment and by foliage treatment, without causing any phytotoxicities of Gramineae field crops, and moreover provide an excellent effectiveness against weeds in paddy fields ~PCT International Publication No. W0 90/09378). The present inventor~
made eYtensive inve3tigations to further improve the herbicidal activity of the triazine derivatives. ~
A3 a result, it has been found that a composition comprisinq the tria2ine derivatives in combination with specific compounds exhibit excellent h.orhir;~ activity which can be unexpected from each property of these compounds and shows a high herbicidal effect at a low dosage and at the same time, has a wide range of herbicidal spectrum. rhe present invention has thus been accomplished.

SUMMARY OF 'rllE: INVENTION
That is, the present invention provides a herbicidal composition comprising as active ingredients triazine derivatives represented by general formula [I]:

H,C~X' A~NH~N~NH2 -- [I]

lwherein A represents (wherein Z~ represents oxygen atom or sulfur atom), or (X2~_~
~ OCE2--(wherein x2 represents methyl group or fluorine atom and n represents 0 or an integer of 1 or 2 ); Rl represents hydrogen atom or methyl group; and Xl represents f luorine atom or chlorine atom] and a compound represellted by general formula [II]:

(R )m~

z2 (OCH2) QCOOR [II]

[whereirL Z represents a nitrogen atom or CH, R represents a fluorine atom, a chlorine atom, methyl group, methoxy group or : ~ -amino group, R3 represents a hydrogen atom, methyl group, NH4, an alkali metal or NH(CH3)2, m represents an integer of 1 to 4 and Q represents 0 or 1].
The present invention also provides a method of controlling weeds by applying the triazine deriYative represented by the general formula [I] and the compound represented by the general formula [II], to the weeds or habitat thereof, either separately or in the form of the composition containing both of them .
DETAIl;ED DESCRIPTION OF THE INVENTION
Specific examples of the triazine deri~atives represented by general formula [I] described above include: 2-amino-4-[1-- 20482~9 (benzofuran-2'-yl)ethylamino]-6-(-fluoro,~-methylethyl)-s-tria~lne H3C--C--C~3 H3 o N

20482~9 2-amino-4- [ 1- ( benzofuran-2 ' -yl ) ethylamino ] -6- ~ a -f luoroethyl ) -s-triazine \ /
''C I ~LCH3 ~o~
2-amino-4- [ 1- ( benzothiophen-2 ' -yl ) ethylamino ] -6- ( a -f luoro, a -methylethyl )-s-triazine ~ r ~I CIH3 N~o~ -2-amino-4- ( a -f luoro, a -methylethyl ) -6- [ 2- ( 3 ', 5 ' -dimethylphenoxy ) -1-methylethylamino 1 -s-triazine H, C H3 C- C-CH3 ~--OCN2 ~CH- NHI~O,Y NH
2-amino-4- ( a -f luoro, a -methylethyl ) -6- [ 2- ( 3 ' f luorophenoxy ) -1-methylethylamino]-s-triazine F HtC-C-CH3 ~O-CH2 CH--NH~O~NH

2-amino-4-(a ~-chloro~a -methylethyl)-6-[2-(3' ,5'-dimethylphenoYy ) -l-methylethylamino ] -s-triazine C~

~--OCH2 CH - NH~O.,Y NH

. _ _ 2-amino-4- ( a -f luoro, a -methylethyl ) -6- [ 2- ( 3 ', 5 ' -dimethylphenoYy) -l-methylethyIamino]-s-triazine ~ OCH3--CHNHJ~NO~NH2 ~ I3C
etc .
The triazine derivatives represented by general formula [ I ] described above may be prepared by various processes. Among these processes, an advantageous process comprises reacting alkyl amine salts represented by general f ormula [ III ]:

A--C~--NH 2 HX9 ... [ Ir I ]
[wherein A has the same significance as described above and X' represents a halogen atom ] with cyanoguanidine represented by ~ 20~8209 the following formula:
NH

to prepare alkyl biguanide salts represented by general f ormula [ IV ¦:
CH, NH NH ... 1 IV]

[wherein A and X~ have the same significances as described above ]; and then reacting the alkyl biguanide salts with alkyl esters represented by general formula rv]

CHt R '--C--COOR -- [ v X' twherein Rl and X: have the same significances as described above; and R~ represents an alkyl group having 1 to 4 carbon atom]. According to this process, the desired triazine derivatives represented by general formula [ I ] can be efficiently obtained by reacting the allcylamine salts represented by general formula [ III I with cyanoguanidine to prepare the alkyl biguanide salts represented by general formula [IV], and then reacting the salts [IV] with the alkyl esters represented by general formula [V].
DETAI~ED DESCRIPTIO~ OF TEiE ~REFERRED E~5BODI~E~iTS
Herein, in the reaction of the alkylamine salts 20482~9 epresented by general formula [III] with cyanoguanidine, both may be used in equimolar amounts. As a solvents, there may be used cyclic hydrocarbons such as benzene, decaline, alkylnaphthalenes, etc.; chlorinated hydrocarbons such as carbon tetrachloride, ethylene dichloride, chlorobenzene, dichlorobenzene, trichlorobenzen, etc. A
reaction temperature is not particularly limited but the reaction sufficiently proceeds at a high temperature ranging from 80 to 200C .
According to this reaction, the alkylbiguanide derivative salts shown by general formula [IV] are obtained.
By reacting [ IV] with alkyl esters represented by general formula [V], the desired triazine derivatives represented by general formula [I] are prepared. ~his reaction efficiently proceeds generally in a solvent such as alcohols, e.g., methanol, ethanol, isopropanol, etc., various ketones, aliphatic hydrocarbons, various ethers, various cyclic hydrocarbons, chlorinated hydrocarbons, etc., in the presence of a catalyst such as a base, etc. at a temperature of about 10 to about 100 C-Optical isomers are also present in these compoundsand the products are obtained generally in the racemic form.
~owever, it is also possible to the respective enantiomers in a conventional manner such as asymmetric synthesis, etc, In the present invention, both racemic compounds and optical isomers alone may be used. In the present invention, the products may be in the form of salts with inorganic acid or ~ 2V482~9 organic acid.
On the other hand, specific examples of the compound represented by general formula [ II ~ described above include 2, 3, 6-trichlorobenzoic acid; 3, 6-dichloro-2-methoxybenzoic acid; 3-amino-2, 5-dichlorobenzoic acid; 2, 3, 5-trichloro-6-methoYybenzoic acid; 4-amino-3, 5, 6-trichloro-2-pyridinecarboxylic acid; 3, 6-dichloro-2-pyridinecarboxylic acid; ( 3, 5, 6-trichloro-2-pyridinyl ) -oxyacetic acid; ( 4 -amino-3, 5-dichl oro- 6 -f luoro- 2 -pyridinyl ) oxyacetic acid, etc . Among them, preferred are 3, 6-dichloro-2-methoxybenzoic acid and ( 4-amino-3, 5 -dichloro-6-f luoro-2-pyridinyl ) oxyacetic acid .
The compounds represented by general formula [II]
can be prepared by known process. These compounds have a spectrum for broad-leaved weeds and are used for crops of corn, wheat, barley, etc. or also in non-cultivated ~ield, etc .
The herbicidal composition of the present inventLon comprise~ as active ingredients the triazine aerivatives represented by general formula [Il described above and the compounds represented by general formula [III described above.
A proportion of these components to be formulated is not particularly limited but in a wide range of proportion, an excellent synergistic ef~ect can be obtained. In general, it is preferred to formulate the triazine derivative and the compounds represented by general formula [II] in a range of from 10: 1 to 1: 100 (weight ratio).
The herbicidal composition of the present invention 20482~9 may be used in the form of wettable powders, emulsiiable concentrates, dusts, granules, flowable concentrates, solutions , etc ., by blending the triazine derivatives represented by general formula [I] described above and the compounds represented by general formula rII] described above with liquid carriers such as solvents, etc. or with solid carriers such as mineral powders, etc. In preparing into these forms, there may be added surfactants such as emulsi~iers, dispersing agents, developers, suspending agents, permeating agents, stabilizers, etc. and, if necessary, other auxiliary agents.
Where the herbicidal composition of the present invention is used in the form of wettable powders, 10 to 55 wt~ of the aforesaid triazine derivatives and the compounds represented by general formula [II] as active ingredients, 40 to 88 wt% of the solid carrier and 2 to 5 wt% of the surfactant may generally be formulated to prepare a composition and the composition may be used. Where the herbicidal composition is used in the form of emulsifiable concentrate or flowable concentrate, 5 to 50 wt% of the aforesaid triazine derivatives and the compounds represented by general formula [II] as active ingredients, 35 to 90 wt%
of the solvent and 5 to 15 wt% of the surfactant and other auxiliary agent may generally be formulated to prepare a composition and the resulting composition may be used.
Where herbicidal composition is used in the form of dust, 1 to 15 wt% of the aforesaid triazine derivatives and _ g _ ~

~ 20~82~9 the compounds represented by general formula [II] as active ingredients and 8 5 to 9 9 wt~ of the solid carrier may generally be formulated to prepare a composition. Wherc the herbicidal composition of the present invention is used in the form of granules, 0.1 to 15 wt% of the aforesaid triazine derivatives and the compounds represented by general formula [II] as active ingredients, 80 to 97.9 wt~ of the solid carrier and 2 to 5 wt~ of the surfactant may generally be formulated to prepare a composition. ~erein, as the solid carrier, f inely divided mineral powders are used . As the f inely divided mineral powders, there are diatomaceous earth, oxides such as slaked lime, etc.; phosphates such as apatite, etc.; sulfates such as gypsum, etc.; silicates such as talc, pyrophyllite, clay, kaolin, bentonite, acid clay, white carbon, quartz powders, silica powders, etc.
As the liquid carrier, there may be organic solvents, for eYample, paraffin type or naphthene type hydrocarbons such as kerosene, mineral oil, spindle oil, etc.; aromatic hydrocarbons such as benzene, toluene, xylene, etc.; chlorinated hydrocarbons such as o-chlorotoluene, trichloromethane, trichloroethylene, etc.; alcohols such as cyclohexanol, amyl alcohol, ethylene glycol, etc.; alcohol ethers such as ethylene glycol monomethyl ether, ethylenen glycol monoethyl ether , etc .; ketones such as isophorone , cyclohexanone, cyclohexenyl-cycl- he~nnne, etc.; ethers such as butyl cellosolve, dimethyl ether, methyl ethyl ether, etc .; esters such as isopropyl acetate , benzyl acetate , methyl -- I O --2~48209 phthalate, etc.; amides such as dimethylformamiae, etc.;
nitriles such as acetonitrile, propionitrile, etc.; sulfoxides such as dimethylsulfoxide, etc.; or a mixture thereof; or water and the like.
As the surfactant, there may be used any of anion type (alkylbenzene sulfonate, alkyl sulfonates, laurinamide sulfonate, etc. ), nonion type (polyoxyethylene octyl ether, polyethylene glycol laurate, sorbitan alkyl esters, etc. ), cation type (dimethyllaurylbenzyl ammonium chloride, laurylamine, stearyltrimethyl ammonium chloride, etc. ) and amphoteric type (amino acids, betaine, etc. ) .
For purposes of improving properties of the preparation and enhancing the herbicidal effect, the herbicidal composition of the present invention may also contain high molecular compounds such as sodium alginate, carboYymethyl cellulose, carboYyvinyl polymer, gum arabic, hydroxypropylmethyl cellulose, etc. and auYiliary agents in combination .
The herbicidal composition of the present invention exhibits an excellent effect on weeds in field crops such as corn, sorghum, wheat, barley, oat, etc., as a high degree of selective herbicide without causing any phytotoxicities to crops by pre- or post-emergence treatment to the soil or the oliage of weeds. The herbicidal composition shows a high herbicidal effect not only against annual weeds but also against perennial weeds and also exhibits an excellent effect of controlling weeds in orchards or non-cultivated fields ~ 1 1 --2~82~9 (factory areas, railways, roadsides, waterways, fallow grounds ), etc., by treatment to the soil or to the foliage of weeds .
The herbicidal composition of the present invention is applied in an amount of about 0.1 to 10,000 g, preferably I
to 1,000 g, per 10 ares. Where the composition is sprayed over the foliage of plant, the composition is diluted to about 1 to about 100,000 ppm, preferably 10 to 10,000 ppm and the diluted preparation is applied to the foliage.
The herbicidal composition of the present invention may also be used in combination with other herbicids.
~xamples of the conventional herbicids which can be used herein include diphenyl ether c _ ~s, triazine compounds, phenoxyacetic acid compounds, carbamate compounds, thiocarbamate compounds, acid anilide compounds, pyrazole compounds, phosphoric acid compounds, sulfonylurea ~1 ~ ls, imidazolinone compounds, dinitroaniline compounds, bromoxinyl, ioxinyI, oxadiazone, etc.
Furthermore, the herbicidal composition of the present invention may also be used as admixture with insecticides, sterilizers, plant growth regulators, fertilizers, etc., if necessary.
Next, the present invention is described with reference to examples.
Firstly, a method for making formulations is specifically described by referring to formulation examples.
n the following formulation examples, "part" refers to ~ by `~ 2048209 weight. As the triazine derivative (Compound A) and the compound represented by general ~ormula [II I (Compound B) compounds shown in Tables 1 and 2 were used, respectively.

20~820~
. ~
Table 1 No . S tructural Formula comoound 2-amino-4- [1- (benzofuran-H3C-C-CH3 2 ' -yl) ethylaminol -6- ( -A-l ~ ~1~ fluoro, -methylethyl)-(~LCH--NH~N~NH2 \ / 2-amino-4- [ 1- (benzof uran-A-2 C,H 2~-yl)ethylamino]-6 (a-fluoroethyl~-s-triazine 2-amino-4- [1- (benzothio- -H C-C-CH phen-2'-yl)ethylamino]-6-A 3 2 3 (-fluoro,-methylethyl)-~LCH--NH~ N ~NH2 ,F 2-amino-4-~ct-fluoro,a-HlC H3C- Ç-CH3 methylethyl-6- ~2--3 ', 5 ' -A-4 '`H dimethylphenoxy)-l-`t 3 ~ O ~ methylethylamino]-s-~'- N~NH2 2-amino-4- (-fluoro,CL-F H3C- Ç-CH3 methylethyl) -6- [ 2- ( 3 ' -A-5 \ ~ ~t~l fluorophenoxy)-l-methyl-Ç 3 ,` o ~ ethylamino]-s-triazine ~O-CHI cll--NH--~ N~NH2 `~ 20482Q9 Table 1 (Continued~
No. ,, uctural Formula ,~ , Comp, ound . ,~
H3C H3C-J~CH3 2-amino-4~ -chloro, C~-~ rH3 ~r ~ methylethyl) -6- [2- (3 ' , 5 ' -A-6 ~OCI~2CH--NH~NOlNH methyleYtPylaminYo]-s-F

_ _ 2-amino-4-(c(-fluoro,O~-A-7 H3C HaC Cr CH3 methylethyl)-6-L2-(3~,5~-CH ~ N dimethylphenoxy)-l-1 3 1 0 I methylethylamino]-s-S~OCHz--CHNH--~N~H2 triazine E~3C ~

` ~ 2~8209 Table 2 Compound No. Structural Formula Name of Compound OCH3 3, 6-dichloro-2-B-l ~COOH methoxybenzoic acid ~ C ~ 3 6-dich - -B-2 1J--C00H ' loro Z

C~) CO (4-amino-3,5-dichloro-B-3 O 6-fluoro-Z-pyridinyl) -`N'--OCH2COOH oxyacetic acid Formulation Example 1 Wettable powders Compound A-1 5 parts Compound B-1 15 parts Diatomaceous earth 62 parts White carbon 15 parts Sodlum alkylbenzenesulfonate Z parts Sodium lignin sulfonate 1 part The foregoing components are blended with each other, uniformly kneaded and ground into powders to give 100 parts of wettable powders.
Formulation Example 2 Emulsifiable concentrate Compound A-2 10 parts Compound B-2 30 parts ~Cylene 20 parts Dimethylformamide 20 parts Solpol 2806}3 (manuactured by Toho Chemical Industry, surfactant) 20 parts The foregoing components are uniformly dissolved and blended to give 100 parts of emulsifiable concentrate.
Formulation Example 3 Dust Compound A-3 0 . 6 part Compound B-3 1. 4 parts Diatomaceous earth 20 parts Talc 78 parts ~ he foregoing components are blended with each other, uniformly kneaded and ground to give 100 parts of dusts .
Trad~-mark ~L - 17 ~ 2~82~9 Formulation Example 4 GranUle Compound A-5 1 part Compound B-2 3 parts`
Bentonite 3 0 parts Talc 63 parts Sodium lignin sulfonate 3 parts The foregoing components are thoroughly blended with each other, uniformly mixed and ground into powders. Water is added to the powders. After kneading them well, the blend is grained and dried to give 100 parts of granules.
Formulation Example 5 Flowable concentrate Compound A-1 l0 parts Compound B-3 15 parts Nethyl cellulose C . 3 part Colloidal silica 1. 5 parts Sodium lignin sulfonate 1 part Polyoxyethylene nonyl phenyl ether 2 parts Water 70 . 2 parts The foregoing components are thoroughly mixed and dispersed. The resulting slurry mixture is subjected to wet grinding to give 100 parts of stable flowable concentrate.
Formulation Example 6 Wettable powders By uniformly blending 97 parts of clay (trademark:
JIKURAITO, manufactured by JIKURAITO KOGYO) as a carrier, 1.5 parts of alkylaryl sulfonate (trademark: NEOPELEX, manufactured by Kao Atlas Co., Ltd.) as a surfactant, 1.5 parts o~ nonionic and anionic surfactant (trademark: Solpol 800A, manufactured by Toho Chemical Industry Co., Ltd. ) and grinding into powders, a carrier for wettable powders was obtained .
By uniformly blending 90 parts of this carrier for wettable powders and 10 parts of the triazine derivative shown in Table 1 t Compounds A-1 through A-7 ) or 10 parts of the compounds shown in Table 2 ( Compounds B-1 to B-3 ) and grinding into powders, wettable powders were obtained.
Furthermore, the carrier for wettable powders containing the tria2ine derivative obtained above was blended with the carrier for wettable powders containing the compounds shown in Table 2 in definite amounts (ratios as active ingredients), uniformly kneaded and ground into powders to give wettable powders .
Example 1 Test on post-emergence treatment Wagner's pots of 1/2000 ares were filled with soil from upland fields and planted with weed seeds of Abu~i lon theDPhrasti, Ipomoea purpurea, Galium aparine L. and Viola arvensis and crop seeds of corn, sorghum, wheat, barley and oat. The seeds were then covered with soil and cultivated in a greenhouse. An aqueous suspension of a definite amount of the herbicide obtained in ~ormulation Example 6 was uniformly sprayed onto the f oliage of 1. 5 to 2 . 5 leaf stage of these weeds and 3 leaf stage of the crops at a spray volume corresponding to 100 liters/10 ares. Then, cultivation was performed in the greenhouse. After 20 days, crop injury and the herbicidal effect on the weeds were evaluated according to 20~8209 the criterion described below. ~he results are shown in Table 3.
(Criterion for ::~C5~q ~) Degree of herbicidal effect Percent of weed control ( herbicidal rate ) 0 less than 5~
( little effectlve) 5-20 %
2 20-40%
3 40-70~

4 70-80%

5 more than 90~
(almost all killed) The herbicidal rate described above was determined according to the following equation by measuring the raw weight of weed on the ground in the treated group and the raw weight of weed on the ground in the untreated group.
Eierbicidal rate ( % ) Weight of weed on the ground in the treated group (1-- ) X 100 Neight of weed on the ground in the untreated group Degree of crop in jury 0 -- no in jury to crops 1 ~-- little injury to crops 2 -- some in jury to crops 3 -- injury to crops 4 -- serious injury to crops 5 -- almost all crops are withered to death Table 3 ~erbicidal EfEoct Crop Injury Active Dosago ingrodient (g/lOa) ASutilon ~poooea Galium Viola theophrasti purpuroa aparine arvensis Co~n 30rghum ~hoat BarleY
, _ A-l 10 3 4 2 3 0 0 0 0 S 1 2 1 2 0 0 0 o Trinzine 5 2 2 1 2 0 0 0 0 DeriYativo A-û 10 3 5 3 4 0 0 0 0 S 2 3 1 2 ~ O O O O

Co-pound B-l 10 3 3 3 2 0 0 0 0 reprosentod S 2 2 2 1 0 0 0 0 by ~ ~ , general B-2 10 3 3 2 3 0 0 0 0 for~ula rll] 5 2 1 1 1 0 0 0 0 -- 21 ~

Table 3 (Contimled) ., . . . ~ ~Y
Triazine Co~pound represented Herbicidal Effert Crop Injury Derivative bY general furmula [Il]
- Abutilon Ipomoer. Galium Viola Rind Dosage Kind Dosage theophrasti purPurea aparine arvensis Corn Sorghum Wheat BarleY
(g/lûa) (g/lOa) ~,.
Al 10 Bl 10 5 5 5 5 O O

S S S S S S O O O O
Al 10 B3 15 5 5 5 5 O O O

O O O O
A2 10 Bl 10 5 5 5 5 O O O O
O O O O
O O O O
O O O O

O O O O
s s s s s s o 8 o o O O O O
b5 5 5 5 o O g A3 10 Bl 10 5 5 5 5 O O O O

O O 'O O
O O O O

]O 5 5 5 5 O O O O
s lo s 8 s s o o o o A4 10 Bl 10 5 5 5 5 O O O O
g b b 5 O O O O
O O O O

O O O O
O O O O

20~8209 Table 3 (Continued) Triazine CoaPound represented llerbicidal eEEect Crop Injury Derivati~re bEY I 8e[lnler]al -~ - Abutilon Ipo~oe Oaliua Viola Klnd D(o/age) Kind Dosage theophrasti purPUrea aparine arvensis Corn 30rghua aheat Barloy AS 10 Bl 10 S S S S 0 0 0 0 S S S S S S O O O O
~ .. .. . .
1510 B3 lS 5 S S S 0 0 0 0 A610 Bl 10 5 S S S 0 0 0 0 s s s s o 8 8 o s 5 5 5 5 5 o o o o A618 B3 10 6 5 5 5 o 0 0 8 ~5 5 5 5 5 o o o o s ~o s - s s s o o o o ~ . , . . ~, A710 Bl 10 5 S S S 0 0 0 0 10 ' 5 5 5 5 5 0 0 0 0 ~ .

S S S S S S O O O O

.

2~4820g Some data were extracted ~rom the re~ults shown in Table 3 and the synergistic effect of the triazine derivative and the compounds represented by general formula [II] was examined on IPomoea purpurea and ViQla arvensis according to the f o l l ow i ng me thod .

Qa- Q~
Q E = Q a+ Q b -- ~

Q a: found data (%) of herbicidal rate when treated at a dosage corresponding to a g/10 ares using the triazine derivative alone as active ingredient Q b: found data (~) of herbicidal rate when treated at a dosage corresponding to b g/10 ares using the compound represented by general formula [II] alone as active ingredient Q E: expected value [Limpel, L.E., P.E~. Schuldt and 3. Lamont, Proc. NEWCC, 16, 48-53 ( 1962 ) ]
~ erein, when the found data (herbicidal rate) of the her~icidal obtained by mixing the triazine derivative and the compounds represented by general formula tII] is larger than Q E, it can be said that the herbicidal activity is synergistic. The results are shown in Table 4.

-- 2~ --20~82~9 Table 4 Tri~7ine Compound reprcsented Derivativn b~ 8er~eral Herbicidal Effect for-uls Lll~ -~ind Dosage l~ind Dosage PerceDt con-rol Sxpected Percent control ~pected (g/lua) WlUa) of lPomoea Value of Viola Value purpurea ~%) (Qc )(O arvensis ~%) (Qc )(%) Al S - - 36 - 38 Al S Bl 10 92 74 90 62 hl S B3 33 77 95 30 A - - - -~ - _ Bl10 83 ; 78 ~ B2 10 82 ~ 87 h B3 lS 85 88 -- . . , . , . ", A3 10 Bl 10 100 89 92 76 AA3 1O 83 IS 72 ~ 9824 88 A4 5 B3 ~ 52 83 ,9328 80 /l _ _ _ . Bl 10 ~ B9 B0 L
B210 ~ 88 88 A B3 lS ~ 90 1 90 A8 S B3 lS 83 87 92 30 h" - - 7~ - Y
~'' Bl 10 9 88 74 h'' - - 7 b~ B2 10 9 87 85 h~ B3 15 10~ 89 , 87 " ~ 2048209 Example 2 Field test (post-emergence treatment test) Test zone having each plot of 2 m' were prepared and weed seeds of Xan~hil~m str~ rium. IPomoea purpurea, AbutilQn theophrasti, Portulaca oleracAA, Solanum ni~ru~, Cassia ob~ if QLia IJ., and AmarAnth~c retroflexl-c and crop seeds of corn and sorghum were simultaneously planted.
When weeds grew at the 2-3 leaf stage and corn and sorghum reached the 3-leaf stage, a given amount of a dilution of the herbicide obtained in Formulation Example 6 was uniformly sprayed onto the foliage at a spray volume corresponding to 20 liters/10 ares. The test was carried out by 3 replications.
The weeds on the ground which survived 30 days after spraying of the chemical were cut out and their raw weights were measured. According to the following equation, a weed controlling rate was determined as an average of the 3 repl icates .

ercent of weed control ( ~ ) =
Weight of survived weed on the ground in the treated plot (1- ~ X 100 Weight of survived weed on the ground in the untreated plot With respect to wheat and barley, their raw weights on the ground were measured also as in weeds and the degree of crop in~ury linhibition rate) was determined. The results are shown in Table 5.

` ~ 2048209 Table 5 Active ingredient A2 + Bl A7 ~ B1 Dosage(g/lOa) 20+20 10+20 20+20 10+20 Percent of Weed Gontrol(%) Xanthium stn~1ari~ 100 100 100 100 Ipomoea purpurea 100 100 100 100 Abutilon theophrasti 100 100 100 100 Portulaca oleracea 100 100 100 100 Solanum nigrum 100 100 100 100 Cassia obtusifolia L. 100 100 100 100 Amaranthus retroflexus 100 100 100 100 . .
Crop Injury Corn O O O O
Sorghum O O O O
, 20482~9 Example 3 Field test (post-emergence treatment test) Test zone having each plot of 2 m' were prepared and weed seeds of Galium aparine L., Stellaria media, Viola arvensis, r5atricaria inQs~Q~, Vernn;ca hedelifoliR PaPaver ~h~ and Aphanes arvensis and crop seeds of wheat and barley were simultaneously planted.
When weeds grew at the 2-3 leaf stage and wheat and barley reached the 3-leaf stage, a given amount of a dilution of the herbicide obtained in Formulation Bxample 6 was un~formly sprayed onto the foliage at a spray volume corresponding to 20 liters/10 ares. The test was carried out by 3 replications.
The percent of weed control and the degree of crop injury were determined 30 days after spraying the chemical in a manner similar to Example 2. The results are shown in Table 6.

` 20482~9 Table 6 Active ingredient A2 + B3 A7 + B3 Dosage(g/lOa) 20+15 10+15 20+15 10+15 Percent of Weed Control(O
Galium aparine L. 100 100 100 100 Stellaria media 100 100 100 100 Viola arvensis 100 IOO 100 100 .~atricaria inodora 100 IOO 100 100 Veronica hedelifolia 100 100 100 100 Papaver rhoeas 100 100 100 100 Aphanes arvensis 100 100 100 100 Crop Iniury Wheat O O O O
Barley O O O O
.

" ~ 204820g By the synergistic effect of the triazine derivative and compounds represented by general formula [II] as active ingredient, the herbicidal composition of the present invention show a high herbicidal effect at a low dosage and also have a wide range oi herbicidal spectrum. Further when the composition is used as herbicide for field crops, the composition has flexibility of treatment to exhibit effectiveness, as compared to in conventional herbicides for field crops. The composition also shows a high herbicidal activity even against troublesome weeds both by treatment to the soil at the pre- or post-emergence of weeds and by treatment to the foliage at the post-emergence of weeds. In addition, no crop injury is caused. In particular, the effect is markedly high in treatment to the soil or foliage treatment in f ields where Gramineae crops grow.
While the invention has been described in detail and with ref erence to specif ic embodiments thereo~, it is apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and the scope of the present invention.

Claims

1. A synergistic herbicidal composition comprising as active ingredients:

a triazine derivative represented by general formula [I]:

[I]

[wherein A represents (wherein Z1 represents oxygen atom or sulfur atom), or (wherein X2 represents methyl group or fluorine atom and n represents 0 or an integer of 1 or 2); R1 represents hydrogen atom or methyl group and X1 represents fluorine atom or chlorine atom], and a compound represented by general formula [II]:

[II]

[wherein Z2 represents a nitrogen atom or CH, R2 represents a fluorine atom, a chlorine atom, methyl group, methoxy group or amino group, R? represents a hydrogen atom, methyl group, NH4, an alkali metal or NH(CH3)2, m represents an integer of 1 to 4 and ? represents 0 or 1].

2. The herbicidal composition as claimed in claim 1, wherein the triazine derivative represented by general formula [I] is a triazine derivative selected from the group consisting of 2-amino-4-[1-(benzofuran-2'-yl)ethylamino]-6-(.alpha.
-fluoro, .alpha. -methylethyl)-s-triazine, 2-amino-4-[1-(benzofuran-2'-yl)ethylamino]-6-(.alpha. -fluoroethyl)-s-triazine, 2-amino-4-[1-(benzothiophen-2'-yl)ethylamino]-6-(.alpha. -fluoro, .alpha. -methylethyl)-s-triazine, 2-amino-4-(.alpha. -fluoro, .alpha. -methylethyl)-6-[2-(3',5'-dimethylphenoxy)-1-methylethylamino]-s-triazine, 2-amino-4-(.alpha. -fluoro, .alpha. -methylethyl)-6-[2-(3'fluorophenoxy)-1-methylethylamino]-s-triazine, 2-amino-4- (.alpha. -chloro, .alpha. -methylethyl)-6-[2-(3',5'-dimethylphenoxy)-1-methylethylamino]-s-triazine and 2-amino-4-(.alpha. -fluoro, .alpha. -methylethyl)-6-[2-(3',5'-dimethylphenoxy)-1-methylethylamino]-s-triazine.

3. The herbicidal composition as claimed in claim 1, wherein the compound represented by general formula [II] is a compound selected from the group consisting of 2,3,6-trichlorobenzoic acid; 3,6-dichloro-2-methoxybenzoic acid; 3-amino-2,5-dichlorobenzoic acid; 2,3,5-trichloro-6-methoxybenzoic acid; 4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid; 3,6-dichloro-2-pyridinecarboxylic acid; (3,5,6-trichloro-2-pyridinyl)-oxyacetic acid and (4-amino-3,5-dichloro-6-fluoro-2-pyridinyl)oxyacetic acid.

4. The herbicidal composition as claimed in claim 2, wherein the compound represented by general formula [II] is a compound selected from the group consisting of 2,3,6-trichloro-benzoic acid; 3,6-dichloro-2-methoxybenzoic acid; 3-amino-2,5-dichlorobenzoic acid; 2,3,5-trichloro-6-methoxybenzoic acid;
4-amino-3,5-6-trichloro-2-pyridinecarboxylic acid; 3,6-dichloro-2-pyridinecarboxylic acid; (3,5,6-trichloro-2-pyridinyl)oxyacetic acid and (4-amino-3,5-dichloro-6-fluoro-2-pyridinyl)oxyacetic acid.

5. The herbicidal composition as claimed in any one of claims 1 to 4, which comprises the triazine compound [I] and the compound [II] at a weight ratio of 10:1 to 1:100.

6. The herbicidal composition as claimed in claim 5, which further comprises a herbicidally acceptable liquid or solid carrier.

7. The herbicidal composition as claimed in claim 6, which further comprises a surfactant.

8. The herbicidal composition as claimed in claim 6, which comprises the triazine compound [I] and the compound [II]
at a weight ratio of 2:1 to 1:3.

9. A method of controlling weeds, which comprises applying the herbicidal composition as defined in claim 5 to the weeds or habitat thereof.

10. The method as claimed in claim 9, wherein the composition is applied to a cultivation field of a crop selected from the group consisting of corn, sorghum, wheat, barley and oat.